Paper
' Paper' is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets. Paper is a versatile material with many uses. Whilst the most common is for writing and printing upon, it is also widely used as a packaging material, in many cleaning products, in a number of industrial and construction processes, and even as a food ingredient – particularly in Asian cultures. History The oldest known archaeological fragments of the immediate precursor to modern paper date to 2nd century BC in China. The pulp papermaking process is ascribed to Cai Lun, a 2nd-century AD Han court eunuch. With paper an effective substitute for silk in many applications, China could export silk in greater quantity, contributing to a Golden Age. Types Construction Construction paper is a tough, coarse, colored paper. The texture is slightly rough, and the surface is unfinished. Due to the source material, mainly wood pulp, small particles are visible on the paper’s surface. It is used for projects or crafts. Dyeing One of the defining features of construction paper is the radiance of its colors. Before the methodology behind construction paper's coloring was introduced, most paper was colored by pigments and vegetable oil, which had weaker staining capabilities, Then, synthetic dyes were developed, which provided a wider range of colors, stronger dyeing strength, and had cheap costs. However, the colors given by synthetic dyes tend to fade over short periods of time, an effect often seen in construction paper, noted by graying colors and brittleness. Sandpaper Sandpaper is a heavy paper with abrasive material attached to its surface. It is used to remove small amounts of material from surfaces. Book paper A book paper (or publishing paper) is a paper that is designed specifically for the publication of printed books. Cottonpaper Cotton paper is made from cotton linters or cotton from used cloths (rags) as the primary material source. Cotton paper is superior in both strength and durability to wood pulp-based paper, which may contain high concentrations of acids. Properties Certain cotton fibre paper is known to last hundreds of years without appreciable fading, discoloration, or deterioration, so it is often used for important documents such as the archival copies of dissertations or theses. As a rule of thumb, for each percentage point of cotton fibre, a user may expect one year of resisting deterioration by use (the handling to which paper may be subjected). Legal document paper typically contains 25% cotton. Cotton paper will produce a better printout than copy paper because it is able to absorb ink better. Cotton paper is typically graded as 25%, 50%, or 100% cotton. Usually it can be checked by holding the cotton paper up to the light and looking just below the watermark for a number. 100% Cotton paper may contain small amounts of acids and should be tested or certified before use for archival documents. Uses Cotton paper is used in some countries' modern banknotes. Wallpaper Wallpaper is a kind of material used to cover and decorate the interior walls of homes, offices, and other buildings; it is one aspect of interior decoration. Types and sizes In terms of methods of creation, wallpaper types include painted wallpaper, hand-printed woodblock wallpaper, hand-printed stencil wallpaper, machine-printed wallpaper, and flock wallpaper. Two of the most common factory trimmed sizes of wallpaper are referred to as "American" and "European" rolled goods. American rolled goods are 27 inches by 27 feet (8.2 m) in length. European rolled goods are 21.5 inches wide by 33 feet (10 m) in length. Approx. 60 square feet (5.6 m2). Environmental impact of paper The production and use of paper has a number of adverse effects on the environment. Worldwide Consumption Worldwide consumption of paper has risen by 400% in the past 40 years leading to increase in deforestation, with 35% of harvested trees being used for paper manufacture. Category:Everyday Objects Category:Rainbow Category:School Supplies Category:Art Supplies